Sound-box for phonographs.



C. B. REPP.

SOUND BOX FOR PHONOGRAPHS.

APPLICATION FILED JAN. 19. 1912.

1 ,1 63,854. Patented Dec. 14, 1915.

Inventor:

Atty.

CLINTON B. REPP, OF NEW YORK, N. Y.

SOUND-BOX FOR PHONOGRAPHS.

Specification of Letters Patent.

Patented Dec. 14, 1915.

Application filed January 19, 1912. Serial No. 672,066.

To all whom it may concern:

Be it known that I, CLINTON B. Barr, 2- cit-izen of the United States, residing in the borough .of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Sound- Boxes for Phonographs, of which the following is a specification, reference being had therein to the accompanying drawings, which form a part thereof.

My invention relates to sound boxesv for phonographs, and more particularly to the means for insulating the sound box casing so as to exclude the vibrations developed in the diaphragm therefrom.

The main object of the invention is to provide a sound box wherein the edges of the diaphragm will be firmly clamped in position through a medium which will absorb any vibrations passing thereto, which will be weather proof and not susceptible to climatic changes, and which will not deteriorate rapidly through aging.

A further object is to provide a structure of this character wherein the edges of the diaphragm will be completely inclosed by the vibration absorbent body so as to eliminate any possibility of vibrations passing to i the metallic portions of the sound box.

it still further object is to provide in a ing the diaphragm which will have a normal tendency to close upon the edge of the diaphragm, thus simplifying its application to the sound box. And a still further object is to provide a sound box wherein the metallic portions within the sound box will be sheathed by a resilient body to prevent the development of sound vibrations in the metallic portions of the sound box adjacent to the sound outlet opening.

The invention consists primarily in a sound box for phonographs, embodying therein a casing having a sound outlet opening therein, a diaphragm, and a cork gashot supporting the edge of said diaphragm, said gasket having oppositely disposed portions adapted to be clamped upon said diaphragm, and means clamping said gasket upon the edgeof said diaphragm; and in such other novel features of construction, and combination of parts, as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended. i

Referring to the drawings: Figure l is transverse section of a sound box embodying my invention; and Fig. 2 is a detail view in perspective of the packing gasket with the diaphragm therein, said diaphragm being broken away, and said gasket being partly broken away.

Like letters refer to like parts in both of said views.

In sound boxes now commonly used in phonographs, the diaphragm is mounted in a metallic sound box, by means of oppositely disposed annular tubular gaskets. While this construction has been found to be capable of good results, it possesses objectionable features such as the susceptibility of the gaskets to a loss of their resiliency through a loss of life in the rubber of which they are made, the susceptibility to rapid deterioration through climatic changes as in machines exported to tropical countries, and the exposure of the ends of the diaphragm between the gaskets to the metallic flange of the sound box, thus in some instances per mitting the transmission of vibrations to the sound box as a result of this exposure.

As a result of extensive experiments in endeavoring to discover a construction of sound box and the supporting gaskets incidental thereto which will not possess these objectionable characteristics, I have ascertained that high efficiency may be secured. by the use of cork gaskets and that such gaskets not only possess degree of. resiliency necessary to prevent the transmission of vibrations thereby to the metallic portions of the sound box, but may be readily compressed about the edge of the diaphragm to firmly secure it in place, and are not affected by climatic conditions to an extent to cause any material loss of efficiency by reason thereof.

In the embodiment of my invention shown in the accompanying drawings, a indicates an ordinary metallic sound box having a pendant edge Z) and a sound outlet opening 0. Seated within the sound box and secured therein by means of the packing gasket and the annular clamp ring (Z. held in place by the screws 6, is a diaphragm 7.

In practice, I have found the form of gasket shown in the drawings to be the most effective in'use as securely holding the diaphragm in position while facilitating its application to the sound box. This gasket comprises a split ring I of cork, having upon the inner surface thereof a channel i adapted to receive the edge of the diaphragm. I split this ring atone point as at 2', so that the ring may be expanded to an extent to permit the diaphragm to be readily insert-ed within same. 7

The channel it is of a depth to receive and completely extend over the edge of'the diaphragm so that when the diaphragm is in place in thesound box, the edge and adjacent to the edge of said diaphragm will be completely inclo sed, thus causing any vibrations passing thereto from said diaphragm to be absorbed by the resilient packing aiforded'by the cork gasket 9 and at the same time interposing a vibrationabsorbing body between the diaphragm and the edge 6.

In my experiments, I have determined that when a phonograph is in operation, the metalof the sound box is itself in vibration, and that these vibrations may be conveyed therefrom and converted into soundwaves.

Inasmuch as the only portion'of the sound box which could transmit vibrations to the metallic portions thereof is the diaphragm,

and as the only portion'of the diaphragm exposed to the metallic portions of the sound" 7 box was the edge thereof, I believe that the" insulation of this edge by means of a re silient packing will secure the desired result of preventing the vibrations of the diaphragm from being transmitted to the metallic portions of the sound box and thus confine the sound vibrations to this diaphragm and to those passing through the sound outlet opening 0. To further guard against the development of sound vibrations I in the metallic portions of the box,I prefer to line theinterior of the top of the box about the sound outlet opening'with a resilient sheathing such as the cork disk j, so that the sound vibrations dueito the dis- 7 placement of air within the sound box will be projected by the diaphragm against this resilient sheathing which w1ll not transmit them to the metallic portions of the box.

' In mounting the diaphragm in the sound box, the sheathing j is first secured within] the sound box with the openingtherein in register with the sound outlet opening 0.

The ends of the packing ring 9' at the out i i are then spread apart and the diaphragm ing a unitarystructure embodying the entire packing gasket. and the diaphragm which may be inserted in the sound'box and secured jin-plaoe'by the clamp ring (Z, the

. desired pressure being developed by means of the screws e." This gasket being impervious to moisture, and not susceptible to deterioration through changes of temperature,

the adjustment of the diaphragm when once effected, becomes permanent and the quality 'of-the tone production will be unimpaired by the ordinary conditions of use. The arrangementof the packing is such as to abtion to the precise details of construction '70 sorb all vibrations passing thereto from shown in the accompanying drawings, it being apparent that such may be varied with out departing from the spirit and scope of the invention Having described my invention, what I claim as new and desire to have by Letters Patent, is

1. A sound box for phonographs embodying therein a casing having a sound outlet opening therein, a diaphragm, the plane of whichis perpendicular to the axis of said sound outlet opening, a corkgasket formed as a split annulus with the ends thereof abutting whereby said gasket may be en larged by separating said ends to permit the insertion of said diaphragm therein, said gasket having parallel plane surfaces and a slot extending partly therethrough intermediate said surfaces and opening within protected 7 the inner periphery thereof whereby a portion 'of'said diaphragm adjacent the entire 7 periphery thereof will be inclosed by said gasket and a portion of said gasket will be interposed between the edge of the diaphragm and said casing and a clamp ring acting upon one entire surface of said gasket whereby the entire portion of the diaphragm adjacent the edge thereof and seated in said slot-is subjected to substantially uniform pressure and is gripped firmly by said gasket;

2 A; sound-box for phonographs embodying therein ametallic circular casing having a sound outlet opening extending axially thereof, an annular vibration absorbent body within said casing about said sound outlet opening, a diaphragm, the plane of which is perpendicular to the axis of said opening, a

cork gasket formed as a split annulus with the ends thereof abutting whereby said gasket may be enlarged by separating said ends to permit the insertion of said diaphragm therein,'said gasket having parallel plane surfaces and a slot extending partly therethrough intermediate said surfaces and opening within the inner periphery thereof whereby a portion of said diaphragm adjacent the entire periphery thereof will be inclosed by said gasket and a portion of' said 'of the diaphragm' and said casing, said gasket bearing upon said .VlbIZltlOIl abgasket will be interposed between the edge In Witness whereof, I have hereunto 9 aflixed my signature, in the presence of two subscribing Witnesses, this 8th day of J ansorbent lining and a clamp ring acting upon uary, 1912.

one entire surface of said asket whereby T T F the entire portion of the diaphragm adja- CLILTOL RAP? cent the edge thereof and seated in said slot Witnesses:

is subjected to substantially uniform pres- FRANK T. W'ENTWORTH, sure and is gripped firmly by said gasket.

EUGENE WENING.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

